This invention relates to the art of microwave generation and more specifically to the art of cyclotron maser amplifiers and oscillators in which stimulated coherent emission of microwave energy occurs by electrons in cyclotron motion in a magnetic field.
It is well known in the art, that in order for a system of free electrons in cyclotron motion to impart a net energy gain to an oscillating electromagnetic field or a wave, a phase bunching mechanism must exist. One such phase bunching mechanism is the relativistic effect of mildly relativistic electrons as taught by U.S. Pat. No. 3,398,376 by Hirschfield entitled "Relativistic Electron Cyclotron Maser". Relativistic electron cyclotron masers are commonly called gyrotrons. A second bunching mechanism is by the nonlinear motions induced by a nonlinear electrostatic field as taught by U.S. Pat. No. 4,253,068 by Barnett entitled "Cyclotron Maser Using a Spatially Nonlinear Electrostatic Field".
It is this second phase bunching mechanism (as described in U.S. Pat. No. 4,253,068) on which the present invention is based. The present invention is a result of the continued research of this topic by the applicant since the time of application of U.S. Pat. No. 4,253,068 and constitutes a significant improvement as will be disclosed in the following discussion. A detailed explaination and theory of the phase bunching mechanism is provided in the U.S. Pat. No. 4,253,068 which will not be repeated in the present disclosure. The reader is referred to U.S. Pat. No. 4, 253,068 and the thesis work of Larry R. Barnett presented at the University of Tennessee, June 1978, entitled "Cyclotron Maser Instability in a Nonlinear Electrostatic Field" for details of the theory and calculations. The results of the theory will be used here.